System of electrical supply.



w. o. WOODLAND. 'SYSTEM o1" ELECTRICAL SUPBLY. A1PLIOAT1oN'1ILBp DBO. a, 1911.

1,04959'62; 1 Pten'ted Jan. 7, 1913.

mom/frs 4 WILLIAMLch-'WoopLANnpor WARREN *o Io.:y

ly, of'zfwhic vthefollowing is ay full,' clear,

and'reitactdescriptip'n. y "":`l\/I"" ivhve'fvti'on rel, ties` generally to a systemof,electlrical'supply"and more particuit larlyfit intolvesa new and improved series lighting-snee:

V'The principalobject of my invention is to proyide fafscries' lighting 'circuit which is, ndi'ictively' controlled, the lsystem being arraig'cd'sothat theploadv may be altered, the 'power' tfact'or remaining substantially eonstant' I Y f" ffurt-herQobjeet' of the invention is to 1 de a'newand'improved 'series lighting System `fwhich'fis inductively -controlled thrvughfpthe. inediumfof a suitable transrmer, ltogether with n reactances in -the' primary andsefc'onda'ry of the said transformer 2b mais.. ji'f.. .y

Qtherfobjects andadvantages of the invfention will appear as the .description theretienlarly .pointed outt and' included in the appended Claims..

Inithe accompanying sheet of drawings I `hai/ e-{setforth diagrammatically in several y"yiews"proposed systems or circuitsfor accomplishingthe. purpose of the invention. -.,3 5 ,A Figureli is a diagrammatic arrangement xoffafseries 'lighting circuit comprising any ,suitable number of. lamps, together with a transformer .having Vtaps on the secondary thereof, 1the secondary circuit being also u-provided ,Witha'v suitable` inductance coil; Fig.,y 21S a ynector diagram villustrating the amountfand-relation of the electro-motive foreesat differentloads, Fig?) is a kdiagrammatic arrang,ement` similar in 4piirgose 'tance,-however,l being placed in the primary fcircuitaFig. ,f4 is a vector ydiagram illustratjingwthe'amount ,and relation ofthe electro:

motive forces at dilerent loads; Fig. .5 is a vLLdiggrammat-icarrangement. o f the lighting f rSpeciteation of Letters Patent.

I, L Patenten aan, 7, 41913.

f1. r Applicationled'December 6, 1911. Serial No. 664,196.

electro-motive forcesof the system' represented in Fig. 5 at different loads.

In series lighting circuits of the character herein described and illust-rated, :the .purpose aimed at is constancy of'current; systems now in use are'at-fault in that they7 vvdo not permit of the user fof the 'partial' load taps onV the transformer without altering the power factor unless the'amount of inductance in the-line is changed at the'ftime the circuit is changed tothese partial load@ taps; Y f v Referring particularly to Figs; 1 and 2, APB". represents the primarycircuit of a suitable transformer,v ASBS the secondary circuit of t-he transformer, while b designates taps, suitable in number, led from certain turns ofthesecondary; BSC' designates a: suitable inductance in the secondary circuit, -together with any lnumber of lamps d. Alfn representingv the amounts and relations of the electro-motive forces (Fig. 2) AC indicates the Working voltage applied to the lamps; BC indicates the volt-age across the inductance coil, this voltage being in quadrature with .the secondary voltage; completing the triangle AB vindicates the square root of the sum of the squares of the two previous voltages or the applied voltage which is the amount the secondary of "the transformer must furnish in order to overcome the im-.

lesser number of lamps, it is apparent that,

since the roltageBC remains constant, the working voltage AC will be altered by a larger percentage than the transformer voltage A B; the new working voltage is repre'- sented by A@ while the i-oltageacross the inductance is be, equal in value to BC, A72' now indicating the voltage which the secondary of the transformer mustfurnish in order .to meet the new conditions; The angle BAC lincreases to AC, such increase indicating a decrease in the power factor. lThe power factor maybe corrected, however-,by reducing the coil voltage BC' but thisis objectionable inasmuch as every time'th/enumber `vof lamps is varied the coil must be changed.`

Insertingthe regulating coil-in' the lprimary circuit, as shown in Fig.A 3, when moving the. lightingcircuit to' any'of t-he'taps- Z) therewith, while AB represents A and by'pla'cing` plied by the inductance will have an op 'efecttc such .maf/" to `Figs. 3 .and .4, AC indicates'thefprimary voltage of th'ettansform'erj. BC the. 'voltage acrssth'e Aind-uct'anoe in series withth'e primary and hence'thevoltage inl t'luadrature voltage. Ifthe secondary circuit is-'moved :to lower taps, suchmovement willyincrease the ratio'of the transformer, or, in' other words, the primary {curren'tgwilldecrease,

such decrease being followedby adecrease in the vvoltage across the inductance Ato an amount'indicated at bc; when this smaller quadrature voltage bc-is combined with the original applied voltage AB the angle BAC' will decrease to bVAc, thereby indicating increased we r factor.

AFrom a lof the above' itis seen .thatbyplacing the inductive regulating coil inthe' p pwer factor will decrease, t e inductive regulating vcoil secondary .the

in the primary the power factor will increase, when the circuit is 'moved toylower taps on the secondary; I have-sldiscovered, however, that there .is a point at'which the inductive regulatingfcoil may be divided, part of the coil being placed in the primary of' thejtransformer and -part of it in ther secondary so that the'power factor will remain substantially constant even though the ratio ofthe transformer is changed by mov-v ingthe lighting circuitv to'lower taps.

eferring particularly 4to Figs. 5 and 6, .APBP indicates .the primary of a suitable transformer; an. inductive regulatin coil BDC is in series therewith; ASBS in 'cates the-l secondaryof the transformer, the regu=. lating coil BSC vbeing in lseries therewith, to-

gether with a desired number' of lamps d; b indicates some partial load taps .on the secondary winding. In the vector diagram of Fig. 6 the ,triangle of lelectro-motive forces thererepresented is such that the angle at A is correct forI apower factor" of inthis diagram' transformation is represented by chan es in the size of the triangle, it being note that for any given power factor the angles of the triangle will remain constant for any size transformer, the length of the lines varying, however, with the size of the transformer.. ac represents the working voltage applied'to. the lamps U; cb is the voltage in quadrature with the working volta e' ac which is supries with the secondary circuit.' ab is the square root of the sum of the squares of these two voltages and is the voltage supplied by the secondary of the transformer. AD' represents the primary voltage of the transformer and has a ratlo to the secondaryvoltage ab equal to the ratio of trans- 'that is, it has been reduce consldering the description of these",-

'secondary win presented `byi'fp'ltjueetiin'g the line fransformnon, fnameli'wfthe pointe; it i. bein seentiatlpe'DAC has nmsd' to t e ange w-t however, being reducedjhythe chan the 'ratio of JL ransformati()jnf'so that lw fle the 'prima -f--lnductancev w's'.- formerly regle-- G,

B5 sentedl y BD it is nowrpresented by in thesamelpm rt-ion 'as the ratio of transformation has n' increased; the in t.'B remains un changed, that is, the angle BAGjhas're- 90 power factor has remainedconsmnt It is to be noted that'the description of.

Figs..5 and 61 is not f'fany triangle.-

whatever but only truefvihen 4it is desired .tokeep the power factorat a'certainwalue, f

say at 80% for a -70%V tap on th ,t'r'ans' former, thatis, when lthe point D divides the -line BC intotwo such rpartsffthat... BD. is- 50% greater than DG. eraf evident -that .under the facts existin that to attain the result specified, the pri-i" mary regulator must be 50% greater than the Y secondary regulator; in case it is desired'to 1b;

hold the power factor constant at some other percentage, the conditions are necessarily. changed, the inventive idea illustrated in the system, however, remaining the same. After a careful examina-tion ofthe lightin tem herein-described'- I have learne that. when the 4quantities are chosen thatthe lpower factor is constantat load and 70% of the full load capacity of the transformer, that the power factor will varybyn a'slight fraction of 1% whenl the transformer is tapped at other points for dierg.; ent percentage loads. The variation from -the constant value of the power f actor, howe ever, `is so small that measuring instruments fail to indicate it, the power factor being substantially constant, thereby ada t)- ing the system to eiicient service un er everyday conditions.

Having thus described my invention, I

claim as new, and desire to secure by Letters.. Patent 1 The combination of a transformer, the

primary circuit lof which is inductivelycontrolled, the secondary circuit ofwhich is 1 80.

Sys- 1rol innesca also inductively-controlled and provided with partial load taps, with la numberv 'of' translating devices in series with the said secondary circuit.

2. A series lighting system comprising a transformer, each circuit of the transformer being inductively-controlled through 'the medium of reactances, the value of the reactances bearing a determined relation With respect to each other, together with a number of translating devices in series with the secondary Winding.

3. A' lighting system comprising' in combinat'ion' a transformer, the secondary winding being provided with partial load taps, a primary reactance, a secondary reactance, the secondary reactance being in series with a number of translating devices, the saidv secondary reactance being of such value that when partial load taps are used the power factor of the circuit will remain sub. 'stantially constant.

4. The combination of a transformer havthe 'secondary reactance,

ing, and translating devices in series with artial load Winding being provided with t e saidsectaps, 'the inductive eect of londary reactance being such that, when the secondary circuit 1s led from one of the said taps, varying the number of translating devices will leave the power factor substantially constant. y

5. The combination of a transformer provided with reactance coils in the primaryV and secondary circuits, andtranslati'ng devices in series in the latter circuit.

-lntestimony whereof I have signed my name to this specification in of two subscribing witnesses. v

WLLIAM C. VVQDLAND.

Witnesses:

L. A. MARTIN, R. H. SNYDER.

the secondary -ing a reactance in the primary oli-f; a reactance in series with the secondary windthe presence 40 

